Several times the candidates have spoken over each other, with moderator Chris Wallace trying to speak above them.
Asked the same question -- will you put U.S. troops into Mosul -- Donald Trump calls the situation in Mosul sad, blamed Hillary Clinton. He says the U.S. had Mosul and lost it while Clinton was secretary of state.
Trump says his plan to defeat IS involves an element of surprise, says U.S. has been stupid in forecasting they were going to try to retake Mosul.